EAGER Collaborative Research: Development of Synthetic Fly Ash Glass as a Model System for Investigating Fly Ash Reactivity

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“EAGER研究的目的是证明使用合成粉煤灰玻璃作为系统研究粉煤灰反应性的模型而不是使用真实的粉煤灰的可行性。 它将证明，合成飞灰试样将产生与实际飞灰一致的反应性数据，而在同一时间，使分析方法的使用，不能用于后者。这将为今后系统研究粉煤灰活性奠定基础。 在这项拟议的研究中，几个粉煤灰玻璃将准备与成分的基础上确定的特征集群在真实的粉煤灰。玻璃粉样品将与整个粉煤灰样品平行水合并进行分析。 此外，典型尺寸为1 cm的合成玻璃整料将在单独的Teflon容器中水合。这种方法能够通过质量平衡定量测定玻璃浸出速率，作为溶液化学和玻璃组成的函数。它还允许随后使用SEM和显微拉曼分析对凝胶层进行详细分析。这对于整个粉煤灰来说是不可行的。这项研究工作将有助于通过对控制反应性的基本因素的更好理解来加速混凝土工业对粉煤灰的使用。这将导致更好地预测粉煤灰玻璃在水泥浆体中的行为的基础上，其反应性，而不是通过传统的试验试错。这反过来将导致更有效地使用粉煤灰，这将提高利用率，并提供废料的经济利用和更低的CO2排放。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."The objective of this EAGER research is to demonstrate the feasibility of using synthetic fly ash glass as a model for systematic studies of fly ash reactivity instead of using real fly ash. It will demonstrate that synthetic fly ash specimens will produce reactivity data consistent with that of actual fly ashes, while at the same time enabling the use of analytical methods that cannot be used on the latter. This will establish the basis for future systematic studies of fly ash reactivity. In this proposed research, several fly ash glasses will be prepared with compositions based on those of characteristic clusters identified in real fly ash. Powdered glass samples will be hydrated in parallel with whole fly ash specimens and analyzed. In addition synthetic glass monoliths with typical dimensions of 1 cm will be hydrated in individual Teflon containers. This approach enables quantitative determination by mass balances of the glass leach rates as a function of solution chemistry and glass composition. It also permits the subsequent detailed analysis of the gel layer using SEM and micro-Raman analysis. This is not feasible for whole fly ashes.This research effort will help accelerate the usage of fly ash by the concrete industry through an improved understanding of fundamental factors controlling reactivity. This will lead to the better prediction of fly ash glass behavior in cement paste based on its reactivity instead of trial and error by conventional tests. This in turn will lead to a more effective use of fly ash, which will increase the utilization rate and provide economical use of a waste material and lower emissions of CO2.